Adjustable Rockers

Douglas Walker

Registered User
I need some input on adjustable rockers. Though some searching Ive found that there has been problems with them coming loose and even pulling out of the head. Also I read that the only way to get them to work properly is to machine the head.
I am wondering if it is worth it to take the chance with adj. rockers or stick with a set of 1.73's.

Thanks
Doug
 
Doug,

If doing it over, I would stay with pedistal mount rockers. I've had numerous rocker stud failures...I think Pro Street Rich, his son Scott and Andy Erickson also had similar problems with the Crane conversion stud and pushrod guide kit.

Many others haven't had any problems...maybe mine was just revved too high. Here is a picture showing the standard Crane stud on the left and the larger shanked Comp Cams Mega stud I'm using now on the right.

stud%20crane&comp.jpg


This is what they look like installed in the heads. To get thenm to fit the tabs on the pedistals had to be milled down about 1/16" to provide clearance for the shoulder of the studs to seat against the pushrod guide, and each of the holes had to be redrilled and tapped to 7/16" NC instead of 5/16" NC.

The holes in the pushrod guide plates was also enlarged to accomidate the larger diameter shank. Then just to be sure they didn't come unscrewed the studs were tack welded to the pushrod guide plates. So far they are holding up fine, but were pretty pricey and I think pedistal mount rockers would have been just as strong or stronger.

heads101103.jpg



stud%20welded.jpg



David
 
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I'm using adjustable pedestal mount 1.73 roller rockers from SuperSix

Here's a link to the .pdf installation manual

They appear to be modified by them to include an adjuster. So far, ~ 20K miles without an issue.
 

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Doug,

Those rockers have the best of both worlds...Strong pedistal mounting and adjustability to set the preload without shimming the rocker pedistals. That's the type I'd use, if doing it again.

David
 
I have 1.8 roller rockers. The car only has about 3000 miles on it since a total rebuild and no problems yet. They are Harland Sharps. I usually dont go over 5600 rpms but have pushed it to 6200 a couple of times with no problems. If I had it to do over I would have used a total bolt on setup with more cam. I would also not have spent the money I did on 351 rods or a double roller timing chain. Sometime I think the stock parts will stand up just as well.
 
DLF said:
I'm using adjustable pedestal mount 1.73 roller rockers from SuperSix

Here's a link to the .pdf installation manual

They appear to be modified by them to include an adjuster. So far, ~ 20K miles without an issue.

I have a regrind cam 520 lift, if I use these roller rockers than I don't need longer pushrods?

thanks
 
Burbank95sc said:
I have a regrind cam 520 lift, if I use these roller rockers than I don't need longer pushrods?

thanks

I'm using the stock pushrods with my .480 regrind. Give SuperSix a call.
 
Are there any issues with clearance inside the stock valve covers? or did you have to take out the factory baffles?
 
1.8 Harland Sharp roller rockers just barley clear the valve covers. The only reason I went with them was that the cam I bought was a little milder than I wanted AFTER I got it all together. My total lift is 500 but it has a lot of duration 260 if I nemember right. For some reason with these rockers it really lopes nice. If I ever did another engine I would probably go with a little over 500 lift. I went with bigger valves so I think that may make up for some of what it lacks in lift. Now it probaably is all the heads will handle anyway.
 
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